• Title/Summary/Keyword: diver

Search Result 116, Processing Time 0.029 seconds

A Field Experiment for the Determination of Drift Characteristics of Person-in-Water (인체의 표류특성 추정을 위한 현장실험)

  • 강신영
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.5 no.1
    • /
    • pp.29-36
    • /
    • 1999
  • A field experiment of the leeway of person-in-water(man with wetsuit) was conducted during October 1997∼ April 1998. The experiment area was northeast side of Cho Do island in Pusan. The college students whose weight ranges 60∼87 kg, height 170∼178 cm were actually drifted for the experiment. The person-in-water wore 5 mm neoprene diving wetsuit to prevent heat loss of the body. The current near the target was measured using a colored vinyl bag. To compare the result a scuba diver equipped with scuba gear and with his BC(buoyancy compensator) fully inflated was drifted alongside. The average leeway speed of man with wetsuit and that of scuba diver were about 0.4 percent and 1.3% of the 10 m wind speed above the water respectively.

  • PDF

Effectiveness Analysis on Comb Pen Shell Based on TAC System (키조개 TAC 제도의 효과 분석)

  • Jeong, Min-Ju;Nam, Jong-Oh
    • The Journal of Fisheries Business Administration
    • /
    • v.47 no.3
    • /
    • pp.15-33
    • /
    • 2016
  • This study aims to analyze effectiveness of the resource use under the total allowable catch system (TACs) of Comb pen shell, a species among TAC targeting ones through its stock assessment based on the surplus production model such as the Clark Yoshimoto Pooley (CYP) model. Particularly, this study is separated into five analysis periods in order to understand changes in Comb pen shell resource and its efficient use after TAC system implemented in 2001. The results of this study are as follows. First, five sustainable yield curves (SYCs) and exponential growth functions (EGFs) produced by the surplus production model based on Gompertz growth function to compare before and after implementation of the Korean TAC system show that the TAC system has generated a positive stock rebuilding effect for Comb pen shell caught by the diver fishery since 2001. Secondly, five profits based on differences between the sustainable total revenue (STR) and the total cost (TC) with respect to fishing efforts present that the TAC system has increased efficiency of resource use of Comb pen shell caught by the diver fishery after implementation of the Korean TAC system. In conclusion, the Korean TAC system has increased efficiency of resource use as well as has led a positive stock rebuilding effect for Comb pen shell.

Analysis of the commercial diving national qualification system for the introduction of a diving supervisor (잠수기능장 제도 신설을 위한 산업 잠수 국가자격체계 분석)

  • Sim, Kyoung-Bo;Cha, Joo-Hong;Kang, Sin-Young
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.40 no.7
    • /
    • pp.655-662
    • /
    • 2016
  • This study proposes that a diving supervisor, who can perform the role of both a field manager and a supervisor, be introduced in the national qualification system. The goal was achieved by surveying the general status of the commercial diving sector, including the statistics of an underwater construction company, commercial diving equipment operation condition, diver working hours, diver supply and demand status, and underwater construction market size. The national qualification and national competency standard (NCS) systems were also analyzed to deduce the role definition and work scope of the diving supervisor. Consequently, the following proposition is made: the diving supervisor should be an "on-site manager with the highest job skill in the commercial diving field, who can perform the on-site process management as well as guide, supervise, and educate project participants and serve as an intermediary between the contractor and the workers." The responsibilities of the diving supervisor are proposed to include "diving planning and operation of the diving team," "diving with surface-supplied air and mixed-gas diving system," "chamber operation," "underwater construction," and "ship salvage." The persistent issues in commercial diving sectors, such as diver career development, management, and worker supervision, are expected to be largely resolved with the introduction of this qualification.

Performance of space -time coding for four transmit antennas on Rayleigh fading channel (4개의 송신 안테나를 사용하는 5-T 방식의 Rayleigh fading에서의 성능)

  • 이은옥;이혁재
    • Proceedings of the IEEK Conference
    • /
    • 2002.06a
    • /
    • pp.41-44
    • /
    • 2002
  • Alamouti proposes a two branch transmit diver-sity scheme that provides the same diversity order as maximal ratio combining at the receiver. It has many advantages of no bandwidth expansion, not requiring channel information at the transmitter and simple maximum likelihood decoding at the receiver. Papadias and Foschini extend this sch-eme to four transmit antennas and suggest several schemes to decrease the interference component and allow the attainment of the open-loop capacity. This paper shows the performance of ZF and MM-SE schemes comparing with ideal case on 4xl sy-stem over BER and 10% outage capacity.

  • PDF

Current status of diving and institutional improvement plan of diving apparatus fishery in the southern coast of Korea (우리나라 남해안 잠수기 어업의 잠수현황과 제도적 개선방안)

  • Heo, Gyeom;Lim, Seok-Won;Shin, Hyeon-Ok
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.51 no.1
    • /
    • pp.136-145
    • /
    • 2015
  • A large number of divers that are engaged in a diving apparatus fishery (DAF) have been experienced a decompression sickness. This study has two purposes. One is measurement of the diving patterns and respiration rate. The other one is to research the institutional improvement plan of the DAF. In the experiments, the diving depth, the diving time, the total ascent time and the ascent rate were about 12.4 m, 22 min, 28 s and 28.1 m/min, respectively, in Tongyeong. In the case of Geoje the diving depth, the diving time, the total ascent time and the ascent rate were about 20 m, 64 min, 17 min and 1.3 m/min, respectively. In a questionnaire survey, the diving depth was 20~29 m (56.4%) in Tongyeong and Geoje, the diving time was 50~59 min (42.9%) in Tongyeong and 70~79 min (35%) in Geoje and all of the divers experienced decompression sickness. In the investigation related to a institutional issue, both of the diving apparatus fisheries had adopted the share system. And the laws and the system for the safety of the divers were not enough in Korea. This study suggests that the license and the diving time for diver of the DAF are needed and diver protection for decompression sickness is needed in the law. And the wage payments should change from full sharing to partial sharing included a regular pay to enhance the safety of the divers.

A Case Report of Complaining of Disturbed Liver Function in Hyperemesis Gravidarium (간기능장애를 동반한 임신악조(姙娠惡阻)환자의 치험 1례(例)에 대한 임상보고)

  • Yoo, Yung-Ki;Bea, Sang-Jin;Kim, Hyung-Jun;Lee, Dong-Nyung
    • The Journal of Korean Obstetrics and Gynecology
    • /
    • v.19 no.4
    • /
    • pp.279-286
    • /
    • 2006
  • Purpose : The purpose of this study is to report the effect of oriental treatments to hyperemesis gravidarum in disturbed liver function. Methods : Hyperemesis gravidarum is a severe and intractable form of nausea and vomiting in pregnancy. It is a diagnosis of exclusion and may result in weight loss; nutritional deficiencies; and abnormalities in fluids, electrolyte levels, and acid-base balance. The peak incidence is at 4, 8-16 weeks of pregnancy. Interestingly, nausea and vomiting of pregnancy is generally associated with a lower rate of miscarriage. However disturbed diver dunction with Hyperemesis gravidarium is rare very and dangerous. Traditionally, oriental medical therapy has been used to patients with hyperemesis gravidarum and showed effective result. We treated 1 patient who had hyperemesis gravidarum in disturbed diver dunction at Se-Myung university Oriental Hospital in affiliation by Herbal medication, acupuncture and moxa therapy and got good result from them. Results : As a result, symptoms are remarkably alleviated and liver function test are improved. Conclusion : Therefore we would like to report that it is effective to cure the hyperemesis gravidarum in disturbed liver function through the herb-medication and acupuncture treatment.

  • PDF

A study on the characteristics of diving accident based on the reports of diving casualties (사례 고찰을 통한 잠수 사고 특성에 관한 연구)

  • Jung Chang-Ho;Lee Chang-Woo;Kim Jung-Man;Kang Sin-Young
    • Journal of Navigation and Port Research
    • /
    • v.30 no.1 s.107
    • /
    • pp.29-34
    • /
    • 2006
  • This study aims to provide divers with improved sqfe diving practices by analyzing reports on scuba diving casualties that recently (from 1997-2003) occurred in Korea, Japan and USA The result of this study may contribute to reduce the diving accident. The data were collected through the diving accident reports of various sources, which include reports of the KUA (Korea Underwater Association) technical committee, the accident statistical data of Korea Coast Guard, articles of domestic and foreign scuba diving magazines, accident reports of various newspapers, annual reports on decompression illness and diving fatalities by DAN (Diver Alert Network), diving accident data reported to local and national seminars, and medical treatment data of diving accident. The analysis focused on the diving casualties and the result showed that the casualty rate in Korea was 2.8 and 2.2 times higher than those in Japan and USA, respectively.

Study on the measurement of the cylinder lengths of an underwater robot for harbour construction using a pressure sensor (압력센서를 이용한 수중항만공사 로봇의 실린더 길이 측정에 관한 연구)

  • Kim, Chi-Hyo;Kim, Tae-Sung;Lee, Min-Ki
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2012.06a
    • /
    • pp.9-10
    • /
    • 2012
  • This paper presents an observer to measure the lengths of cylinders of an underwater robot for harbour construction using a pressure sensor. In harbour constructing, we place heavy armour stones weighing over 2~3 tons on the surface of the bank to protect it from storming wave. This work typically done by a diver is difficult and dangerous so that we have developed Stone Diver which is the underwater robot for harbour construction. The robot needs a position sensor to control the hydraulic cylinder. The position sensors mounted outside the cylinders cause poor durability in construction site where shock and dust usually occur. However, the pressure sensor mounted inside a waterproof box improves the durability. Based on the dynamic parameters and the pressures in the cylinder, the observer measures the cylinder's position. This paper presents the positional accuracy of the pressure based observer and the performance of the underwater robot to assemble the armour stones.

  • PDF